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Status of Eyefinity Support in Linux

05-21-2010, 04:46 PM

Hello,

I am confused about the current state of Eyefinity support in linux. I will say what I want to do and hopefully someone will understand better if it is possible yet.

So I have 4 DVI monitors that are currently run off nvidia cards, it works ok, could be better. I would like to buy two 5XXX cards with 2 DVI outs each and run the monitors as one big desktop using Eyefinity.

I think this will be possible in the future but I can't find out if it is now. I have seen the 24 monitor linux demo, off 4 cards. I have also noticed that the windows drivers seem to support 8 monitors off two cards.

So I have 4 DVI monitors that are currently run off nvidia cards, it works ok, could be better. I would like to buy two 5XXX cards with 2 DVI outs each and run the monitors as one big desktop using Eyefinity.

That's not "Eyefinity" then. To join multiple GPUs into a single big screen, you'll still need Xinerama (or similar), no matter who built the GPU.

Eyefinity is about attaching more than two monitors to a single GPU, so you can avoid using Xinerama. To my knowledge, that works fine on linux using fglrx.

It's unfortunate that there's no option for more than two DVI monitors on a single evergreen GPU, though. Those active converters are expensive, so are new DP monitors

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Well how did they demo a flight sim on 24 monitors with 4 cards in linux? It can't have been using xinerama it would never have worked, the performance is rubbish. The windows Eyefinity states that it works with multiple cards, I should dig up the link for that....

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Not sure what they used, but it should be possible with both Xinerama or (more likely) DMX.

I haven't heard of any ATI-specific replacement for those things, neither of plans to provide any. Then again, there's code in fglrx for multi-GPU-cards, not sure if any of that is usuable with multiple GPUs on separate cards.

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I guess I was assuming that Eyefinity presents all the screens as one big desktop to the OS.

I haven't tried but I think that running a flight sim on my qaud monitor setup would result in very low frame rates. Maybe I should give it a go to see. Maybe I could just get better performance from beefier GPU's. I will wait and see if Phoronix do a review that clears things up.

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Eyefinity is about attaching more than two monitors to a single GPU, so you can avoid using Xinerama. To my knowledge, that works fine on linux using fglrx.

Excuse my noobness and first post, but you're saying more than two monitors works on a single GPU (5870 in my case) with the latest 10.4 ATI drivers?

It's unfortunate that there's no option for more than two DVI monitors on a single evergreen GPU, though. Those active converters are expensive, so are new DP monitors

I have three Dell 2210 each with DP, DVI and VGA. I have two connected through DVI and one DP. I know all three work (not simultaneous) because when I go through install, the DVI on the far right will work fine during the install until the reboot, at which point I can only use the other DVI and DP monitors (middle, left).

xrandr shows all three monitors but I get something like no crtc found for the third monitor. Googling and trying to manually set it doesn't work. The CCC shows all three monitors, but the third DVI monitor is always greyed out, unable to manipulate it.

I've scoured the forums, google and everything else I could think of and read quite a few accounts of people running more the two monitors using separate display cards when going more than two, but not a lot of luck finding a working example of three or more on a single GPU.

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I'm saying that "to my knowledge" it should work. But I haven't actually tried because I lack a DP monitor.

It must work on windows, have you tried that?

If it still doesn't work on windows, then there's a possibility that dell is going the stupid route and it's DP port relies on the DVI routing capabilities of DP. Which would suck a lot, but may explain why they're so cheap.

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I'm saying that "to my knowledge" it should work. But I haven't actually tried because I lack a DP monitor.

It must work on windows, have you tried that?

If it still doesn't work on windows, then there's a possibility that dell is going the stupid route and it's DP port relies on the DVI routing capabilities of DP. Which would suck a lot, but may explain why they're so cheap.

If it works on windows, then it looks like a fglrx driver issue.

Btw, which "Dell 2210" exactly? There are several products with 2210.

P2210H are the three I have. One off DP and two off the two DVI ports in the back of the 5870.

Yes Eyefinity works fine in Windows XP/7 for a display resolution of 5760x1080.

Ubuntu 10.04 was strange. When installing, it used the 2nd DVI monitor to the right. After install and reboot, it used the center DP monitor. Once I loaded the ATI 10.4 drivers, the 1st DVI and DP monitor (left and center) work fine.

xrandr detects three monitors, but always throws crtc errors when trying to work with the second (right) DVI monitor.

If I unplug a monitor (doesn't matter which) it will work fine with the two monitors that are plugged in no matter if it's DVI/DVI or DVI/DP (even tried VGA and HDMI with the above combinations and that produced the same results)

I can boot over shortly here and get some exact numbers if you want to see them (xorg.conf and xrandr output and all that) but I've spent about 15 hours so far trying to get things up and going and while the two monitors @3840x1080 definitely works great, I'm spoiled to three

On the other hand, the list is from Quridarium, so the big question is if it is real.

Well how did they demo a flight sim on 24 monitors with 4 cards in linux? It can't have been using xinerama it would never have worked, the performance is rubbish. The windows Eyefinity states that it works with multiple cards, I should dig up the link for that....

I don't think they ran a normal fglrx driver for that demo. I suppose they hacked together a driver that worked good enough for the flightsim, but might have many issues for nearly all other applications. They might even have changed the entire driverstack.

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I don't think they ran a normal fglrx driver for that demo. I suppose they hacked together a driver that worked good enough for the flightsim, but might have many issues for nearly all other applications. They might even have changed the entire driverstack.

I hope that is not the case. I will be waiting to see what happens anyway. I might squeeze extra performance out of what I have if I upgrade the GPUs.